The prevalence of obesity has risen dramatically among children in the U.S. and throughout the world since the 1960s. Many factors are thought to have contributed to the epidemic of pediatric obesity. One factor that has received increasing attention is consumption of sugar-sweetened beverages. Feeding studies suggest physiological mechanisms by which sugar in liquid form may be less satiating than other foods. An observational study found total energy consumption to be greater among children who consume sugar-sweetened beverages compared to non-consumes. Short-term interventional studies report increasing energy intake and body weight in subjects given sugar-sweetened beverages compared to non-caloric beverages. Our preliminary data found that the risk for becoming obese increased by about 60% in middle school children for every additional serving per day of sugar-sweetened beverage consumed. The Specific aim of the parent grant is to determine how diet quality and body weight change after reducing consumption of sugar-sweetened beverage consumption in high school students in the U.S. The purpose of the present application is to extend this aim to an even higher risk population using a potentially more power intervention. Specifically, we seek to conduct a 4-month clinical trial involving 96 children ages 8 to 11 years in Chile, a developing nation characterized as undergoing a "nutrition transition." The subjects, selected for current sugar-sweetened soft drink consumption, will be randomly assigned to intervention or control groups. The intervention group will be encouraged to substitute milk products for soft-drinks; to facilitate this dietary change, a variety of milk products will be delivered to subjects' homes on a weekly basis. Clinical endpoints include changes in dietary quality, body weight, adiposity by DEXA-scan and measures of calcium homeostasis. A successful outcome of this study would provide 1) novel insights into the effects of diet on body weight regulation; 2) foundations for an inexpensive approach to the prevention of obesity and related complications in children, growing public health problems throughout the developing world. This research will be done primarily in Chile at INTA in collaboration with Professor Cecilia Albala as an extension of NIH grant# 1R01 DK63554 (dates 9/30/02 to 9/29/04).